[torsampo]

Posting this as a heads up and with the hope that someone else has encountered this issue and has a fix:

I am running the Windows 10 Pro Insider Preview build 11090 (recently upgraded from 11082). I have two MTP devices: a Lumia 950 XL and an AK120 II media player- until recently both worked as expected: I could manage files with File Explorer and interact with the devices via my music syncing software, Jriver Media Player and (as a test) Windows Media Player. Now however, while File Explorer can still see and interact with the devices, neither device is detected by my sync apps. Neither Windows Media Player or JRiver Media Center recognize or interact with the devices.

I was able to replicate the issue. On a PC with Windows 10 build 10586.36 I connected my MTP devices and verified the devices are usable by File Explorer and my sync apps (Jriver and WMP). I then updated that PC to Preview build 11099 and found that while File Explorer can still access my MTP devices my syncing software cannot. This definitely seems related to the build. I have not had this issue on builds prior to 11082.

[CFC]

Thanks for confirming this.
I upvoted your entry in the W10 feedback system as well.
Glad you wrote because I wouldn't have been as eloquent.
I have no fix unfortunately, but at least I don't need to pull my hair out since the problem isn't just on my side.

Thanks!
CFC